INA's Ivana D gas platform sank in the northern Adriatic in December 2020 due to material fatigue and bad welds, the company's management told a news conference in Zagreb on Wednesday.

The executives who held the news conference said that the construction of that platform had not been fully aligned with the original project.

Ivana D was put into operation in January 2001, and was in use until its sinking in early December 2020. The platform wreck is now on the seabed at the depth of 41 metres.

INA’s Operating Director of Exploration & Production Nikola Misetic said that two independent investigations conducted by Bureau Veritas and Zagreb’s Faculty of Mechanical Engineering and Naval Architecture show that the accident was caused by the synergy of several factors.

The design of the platform was appropriate for the weather conditions at the Adriatic, however, some inconsistencies in the material of which the platform was built and errors in welds were detected, said the director.

Ivana D was supposed to be in use for at least 40 years.

Misetic says other gas platforms in the Adriatic are safe and secure and they differ from Ivana D in their design and construction.

He explained that Ivana D was a unique platform, that is a monopod with a narrower base.

INA has forwarded the findings of the two independent analyses to the task force authorised to investigate disasters in such cases, which was set up by the economy ministry.

No gas leaks or adverse environmental effects have been noticed so far at the site where Ivana D lies, said the director.

Ivana D as artificial reef

The rig for Ivana D will be cemented at the start of 2023. The Ruđer Bošković Institute (RBI) has proposed that the platform wreck should be kept at the current site on the seabed as an artificial reef.

Not far from Ivana D, a new platform worth 26 million dollars could be set up, according to INA’s plans.

€267m to be invested in new platforms and rigs in Adriatic

This September, the leading Croatian oil and gas group will launch a new campaign for gas exploitation in northern Adriatic areas, and it plans to invest two billion kuna (€267 million) for digging new rigs and building new platforms.

The project, which will boost Croatia’s energy security, envisages nine rigs and the installation of seven platforms. The first gas supplies from new rigs can be expected in 2024, said Misetic.

This will raise the current 30% share of Adriatic sources in the total gas production in Croatia to 40%, he explained.